Pallets are load bearing structures used to provide a stable platform for the storage, transportation or shipment of materials. The materials are often strapped or bound and then placed and/or stacked onto the pallet.
It is known to provide pallets with feet or other structures to raise the pallet off a support surface such as the ground, in order to allow a forklift blade to move under the pallet and to lift the entire load. While pallets are often made of wood, it is desirable to thermoform plastic pallets. Such plastic pallets are often stronger, less expensive, and less susceptible to degradation caused by weathering or the like than their wooden counterparts. Structures such as the feet, strengthening grooves and other components, may be formed in the pallets during the thermoforming operation. It is known to form "twin sheet" pallets, such that two sheets are softened and thermoformed together to make the finished pallet.
One method of forming pallets, including twin sheet pallets, has been to provide a first and second mold sections. A separate plastic blank sheet is then formed to each mold section, such as by vacuum-forming, and the two mold sections are then brought together under pressure until the plastic blank sheets, still at elevated temperatures from the vacuum-forming process, are in contact. The sections of the plastic blank sheets that are in contact are pressed together such that they actually fuse into a solid portion.
It has been known to further strengthen plastic pallets by the use of a reinforcing substructure or framework. Such substructures are often made of metal or wood. For example, a metal framework may be employed such that the pallet is thermoformed around the framework, such as by having the framework "sandwiched" between the two sheets of a twin sheet pallet.
Pallets having a metal or even wooden reinforced substructure are generally stronger than their non-reinforced counterparts. However, the substructures often dramatically increase the weight of the pallet. In storage and shipping operations, weight is usually a primary concern, and a pallet having an increased weight would likely be detrimental to the pallet's overall desirability.
Further, heretofore, while reinforced pallets have been known, such do not provide for improved resistance to torsional stresses at the outer edges of the pallets. Pallets are often stacked one on top of another for storage and transportation. The pallets are often stacked upon their outer edges. It is also sometimes the case that loaded pallets, that is, pallets bearing a load thereon, will be lifted by the edges of the pallet. Known reinforced pallets will not successfully compensate for induced edge stresses, which often result in torsional forces being applied to the pallet edges.
A need exists, therefore, for a reinforced pallet which does not dramatically differ in weight compared to an unreinforced counterpart, and which is successfully reinforced against induced torsional edge forces.